Generic cam followers are already known from DE 197 00 736 A1 and from JP 05-044410 A. In relation to cam followers which, for the alternating transmission of different cam elevations, have housing parts which are movable relative to one another and which can be coupled to one another by means of a pin locking arrangement which has a degree of play, these generic cam followers have a considerable advantage in that the unavoidable scatter in the pin play leads to deviating elevations of the gas-exchange valves, which adversely affect the charge exchange of the internal combustion engine. A further advantage of such cam followers is that the elevations, which are different from one another, of the cams need not be completely nested one inside the other, as is the case on account of the alternating contact, which is to be avoided, of the cams on the associated cam pick-off surfaces of the housing parts in the above-specified cam followers with a form-fitting pin locking arrangement.
The cam followers known from the cited documents do however have some disadvantages with regard to their structural design. Specifically, this relates to the structural series arrangement composed of the piston, which delimits the pressure medium space of the cylinder-piston unit, and the roller which is acted on with a reciprocating movement by the piston. Such a series arrangement leads not only to a voluminous installation space requirement of the cam follower in the direction of the roller axle, but also, on account of the mass action of the moving components, to an impairment of the attainable switching speed of the roller. However, since its switching process must be completed within the common base circle angle of the cams, and the time available for this, as is generally known, decreases with increasing rotational speed of the internal combustion engine, an excessively low switching speed would lead to a considerable restriction of the switching rotational speed, and consequently of the thermodynamic potential of the valve drive variability obtained by the cam follower.